The present invention relates to a lighting unit and in particular to a track lighting unit and to the interconnection of housing parts of the unit and the mounting of a lens within the unit.
A conventional track lighting unit depicted in FIG. 1 comprises an adapter 1 configured to be slidably inserted within a wall-mounted or ceiling-mounted track (not shown), a hollow post 2 extending downwardly from the adapter, and a housing 3 mounted at the lower end of the post. The housing 3 is rotatable relative to the post about a horizontal axis L, and the post 2 is rotatable relative to the adapter about a vertical axis L', in order to adjust the orientation of the housing 3.
The housing 3 comprises upper and lower parts 3U,3L that are releasably secured together. The upper part 3U includes a chamber in which is disposed a lamp-mounting device 4A for mounting a lamp 4 such as an MR-16 lamp. The wiring for the lamp extends through the post 2. A fixed plate 5 extends vertically in the chamber for receiving a spring clamp 6 attached to the lower housing part 3L in order to frictionally attach the two parts 3U,3L together.
Disposed in a casing of the lower housing part is a baffle 7 which includes a cylinder 7A forming a light-emitting passage 7B aligned with the lamp 4. A flat lens 8 (formed for example of glass) is disposed across the top of the cylinder 7A in alignment with the lamp 4 for achieving a desired optical effect. The lens is held in place by metal retaining springs 9. Each spring is secured to a boss 9A formed on the lower housing part by a screw 9B which also functions to attach the baffle to one of the bosses 9A.
It will be appreciated that the assembling of the lower housing part, baffle and retaining springs is cumbersome and time consuming, especially due to the need to attach the screws 9B in a confined area within the lower housing. Special tools are required to make such an attachment because of the confined area.
Therefore, it would be desirable to provide a light assembly which facilitates the mounting of the lens-carrying baffle.